ClimaMeter
Understanding Extreme Weather in a Changing Climate
ClimaMeter is an experimental rapid framework for understanding extreme weather events in a changing climate based on looking at similar past weather situations. Find out more here and follow us on X.
ClimaMeter is an experimental rapid framework for understanding extreme weather events in a changing climate based on looking at similar past weather situations. Find out more here and follow us on X.
November 2024 floods in Colombia mostly exacerbated by human-driven climate change
November 2024 floods in Colombia mostly exacerbated by human-driven climate change
On November 8 and 9, 2024, Colombia’s Pacific coast faced severe flooding due to extreme rainfall driven by a set of meteorological factors. Rainfall intensity reached up to 200 mm/day, causing the Atrato, San Juan, and Baudó rivers to overflow. Chocó, a department with high poverty rates and fragile infrastructure, was the most affected, with 85% of its territory and 188,000 people impacted. The flooding has resulted in a humanitarian crisis, prompting the government to declare a nationwide state of emergency for one year to accelerate aid and recovery efforts.
On November 8 and 9, 2024, Colombia’s Pacific coast faced severe flooding due to extreme rainfall driven by a set of meteorological factors. Rainfall intensity reached up to 200 mm/day, causing the Atrato, San Juan, and Baudó rivers to overflow. Chocó, a department with high poverty rates and fragile infrastructure, was the most affected, with 85% of its territory and 188,000 people impacted. The flooding has resulted in a humanitarian crisis, prompting the government to declare a nationwide state of emergency for one year to accelerate aid and recovery efforts.
ClimaMeter found that meteorological conditions similar to those producing Colombia Floods are up to 37 mm/day (an increase of up to 40%) wetter over the Northern Pacific coast of Colombia and 10 mm/day drier inland in the present than they have been in the past. Additionally, conditions are up to 5 km/h (up to 20%) windier offshore Colombia and up to 1.5 ºC warmer inland in the present compared to the past. We interpret the Colombia floods as an event driven by very exceptional meteorological conditions. Natural variability alone cannot explain the changes in precipitation and wind associated with this very exceptional meteorological condition.
ClimaMeter found that meteorological conditions similar to those producing Colombia Floods are up to 37 mm/day (an increase of up to 40%) wetter over the Northern Pacific coast of Colombia and 10 mm/day drier inland in the present than they have been in the past. Additionally, conditions are up to 5 km/h (up to 20%) windier offshore Colombia and up to 1.5 ºC warmer inland in the present compared to the past. We interpret the Colombia floods as an event driven by very exceptional meteorological conditions. Natural variability alone cannot explain the changes in precipitation and wind associated with this very exceptional meteorological condition.
Heavy Precipitations in South-Eastern Spain DANA mostly strengthened by human-driven climate change
Heavy Precipitations in South-Eastern Spain DANA mostly strengthened by human-driven climate change
Extreme thunderstorms associated with high-level depression (DANA, in Spanish) hit the eastern Spanish coast, leading to unprecedented rainfall, with up to 630 mm recorded in Toris, Valencia, over 24 hours. The Valencian Community bore the brunt of these catastrophic events, facing severe floods, hailstorms, and tornadoes that resulted in over 200 deaths, dozens of missing persons, and widespread devastation, especially in Valencia, Castellón, Málaga, and Albacete
Extreme thunderstorms associated with high-level depression (DANA, in Spanish) hit the eastern Spanish coast, leading to unprecedented rainfall, with up to 630 mm recorded in Toris, Valencia, over 24 hours. The Valencian Community bore the brunt of these catastrophic events, facing severe floods, hailstorms, and tornadoes that resulted in over 200 deaths, dozens of missing persons, and widespread devastation, especially in Valencia, Castellón, Málaga, and Albacete
Based on the above, we conclude that depressions similar to the DANA that cause floods in southeastern Spain are up to 7 mm/day (an increase of up to 15%) wetter over the Mediterranean coast of Spain in the present than they would have been in the past. Additionally, conditions are up to 3°C warmer in the present compared to the past, which favors the formation of thunderstorms over the Mediterranean basin during DANA events. We interpret this DANA as an event driven by very exceptional meteorological conditions, whose characteristics can mostly be ascribed to human driven climate change. We remark that, for this event, we have low confidence in the robustness of our approach given the available climate data, as the event is very exceptional in the data record. To ensure robustness of our findings, we have increased the statistics of analogues to include 20 similar events in past and present periods.
Based on the above, we conclude that depressions similar to the DANA that cause floods in southeastern Spain are up to 7 mm/day (an increase of up to 15%) wetter over the Mediterranean coast of Spain in the present than they would have been in the past. Additionally, conditions are up to 3°C warmer in the present compared to the past, which favors the formation of thunderstorms over the Mediterranean basin during DANA events. We interpret this DANA as an event driven by very exceptional meteorological conditions, whose characteristics can mostly be ascribed to human driven climate change. We remark that, for this event, we have low confidence in the robustness of our approach given the available climate data, as the event is very exceptional in the data record. To ensure robustness of our findings, we have increased the statistics of analogues to include 20 similar events in past and present periods.
Italy Multiple Floods mostly strengthened by Human-driven Climate Change
Italy Multiple Floods mostly strengthened by Human-driven Climate Change
Between October 18 and 19, severe storms and heavy rainfall caused widespread flooding in parts of Italy and central France. Emilia Romagna in Italy was hardest hit, with over 160 mm of rain in Bologna in just four hours, leading to dangerous flooding and over 3,000 evacuations across the region. A young man tragically died after being swept away by a flood in Pianoro. The flooding affected cities such as Ravenna, Modena, and Reggio Emilia, while the overflowing of rivers and streams caused further damage. More than 300 firefighting operations took place, particularly in Bologna.
Between October 18 and 19, severe storms and heavy rainfall caused widespread flooding in parts of Italy and central France. Emilia Romagna in Italy was hardest hit, with over 160 mm of rain in Bologna in just four hours, leading to dangerous flooding and over 3,000 evacuations across the region. A young man tragically died after being swept away by a flood in Pianoro. The flooding affected cities such as Ravenna, Modena, and Reggio Emilia, while the overflowing of rivers and streams caused further damage. More than 300 firefighting operations took place, particularly in Bologna.
ClimaMeter found that the meteorological conditions triggering multiple floods in Italy were extremely rare, in terms of strength and intensity, compared to the historical record of similar storms. There are few historical records that match the intensity of the storm. Mediterranean depressions similar to that causing multiple floods in Italy in October 2024, show increased precipitation (up to 10 mm/day, or up to 25% more precipitation) and produce stronger winds (up to 6 km/h, representing a 10% increase in wind strength) in the present compared to the past. Natural phenomena such as the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation may have played a role alongside human-driven climate change, mostly in driving the trajectory of the depression causing the floods.
ClimaMeter found that the meteorological conditions triggering multiple floods in Italy were extremely rare, in terms of strength and intensity, compared to the historical record of similar storms. There are few historical records that match the intensity of the storm. Mediterranean depressions similar to that causing multiple floods in Italy in October 2024, show increased precipitation (up to 10 mm/day, or up to 25% more precipitation) and produce stronger winds (up to 6 km/h, representing a 10% increase in wind strength) in the present compared to the past. Natural phenomena such as the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation may have played a role alongside human-driven climate change, mostly in driving the trajectory of the depression causing the floods.
Other Recent Extreme Events
Other Recent Extreme Events
